Method of producing a thin silicon-on-insulator layer.

摘要

A method of forming a thin silicon SOI layer by wafer bonding, the thin silicon SOI layer being substantially free of defects upon which semiconductor structures can be subsequently formed, is disclosed. The method comprises the steps of: a) providing a first wafer comprising a silicon substrate (10) of a first conductivity type, a diffusion layer (12) of a second conductivity type formed thereon and having a first etch characteristic, a thin epitaxial layer (14) of the second conductivity type formed upon the diffusion layer and having a second etch characteristic different from the first etch characteristic of the diffusion layer, and a thin oxide layer (16) formed upon the thin epitaxial layer; b) providing a second wafer comprising a silicon substrate (18) having a thin oxide layer (20) formed on a surface thereof; c) wafer bonding said first wafer to said second wafer so that said thin oxide layers (16,20) bond to form a thick oxide layer (22); d) removing the silicon substrate (10) of said first wafer in a controlled mechanical manner; and e) removing the diffusion layer (12) of said first wafer using a selective dry low energy plasma process to expose the underlying thin epitaxial layer (14), the selective dry low energy plasma process providing an etch ratio of the first etch characteristic to the second etch characteristic such that the diffusion layer is removed with minimal formation of any shallow plasma radiation damage to the exposed underlying thin epitaxial layer. The exposed thin epitaxial layer (14) may be then used as standard to form active/passive devices.